Configuring NBAR Using the MQC

Last Updated: November 20, 2011

After you enable Protocol Discovery, you can configure Network-Based Application Recognition (NBAR) using the functionality of the Modular Quality of Service (QoS) Command-Line Interface (CLI) (MQC). The MQC uses traffic classes and traffic policies (policy maps) to apply QoS features to classes of traffic and applications recognized by NBAR.

This module contains concepts and tasks for configuring NBAR using the MQC.

Finding Feature Information

Your software release may not support all the features documented in this module. For the latest feature information and caveats, see the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the Feature Information Table at the end of this document.

Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to
www.cisco.com/go/cfn. An account on Cisco.com is not required.

Prerequisites for Configuring NBAR Using the MQC

Before configuring NBAR using the MQC, read the information in the "Classifying Network Traffic Using NBAR" module.

As applicable, enable Protocol Discovery and use it to obtain statistics about the protocols and applications that are used in your network. You will need this information when using the MQC.

Note

This prerequisite assumes that you do not already have this information about the protocols and applications in use in your network.

Information About Configuring NBAR Using the MQC

NBAR and the MQC Functionality

To configure NBAR using the MQC, you must define a traffic class, configure a traffic policy (policy map), and then attach that traffic policy to the appropriate interface. These three tasks can be accomplished by using the MQC. The MQC is a command-line interface that allows you to define traffic classes, create and configure traffic policies (policy maps), and then attach these traffic policies to interfaces.

In the MQC, the class-map command is used to define a traffic class (which is then associated with a traffic policy). The purpose of a traffic class is to classify traffic.

Using the MQC to configure NBAR consists of the following:

Defining a traffic class with the class-map command.

Creating a traffic policy by associating the traffic class with one or more QoS features (using the policy-map command).

Attaching the traffic policy to the interface with the service-policy command.

A traffic class contains three major elements: a name, one or more match commands, and, if more than one match command exists in the traffic class, an instruction on how to evaluate these match commands (that is, match-all or match-any). The traffic class is named in the class-map command line; for example, if you enter the class-mapcisco command while configuring the traffic class in the CLI, the traffic class would be named "cisco."

The match commands are used to specify various criteria for classifying packets. Packets are checked to determine whether they match the criteria specified in the match commands. If a packet matches the specified criteria, that packet is considered a member of the class and is forwarded according to the QoS specifications set in the traffic policy. Packets that fail to meet any of the matching criteria are classified as members of the default traffic class.

NBAR and the match protocol Commands

NBAR recognizes specific network protocols and network applications that are used in your network. Once a protocol or application is recognized by NBAR, you can use the MQC to group the packets associated with those protocols or applications into classes. These classes are grouped on the basis of whether the packets conform to certain criteria.

For NBAR, the criterion is whether the packet matches a specific protocol or application known to NBAR. Using the MQC, network traffic with one network protocol (citrix, for example) can be placed into one traffic class, while traffic that matches a different network protocol (gnutella, for example) can be placed into another traffic class. Later, the network traffic within each class can be given the appropriate QoS treatment by using a traffic policy (policy map).

You specify the criteria used to classify traffic by using a
matchprotocolcommand. The table below lists some of the available
matchprotocolcommands and the corresponding protocol or traffic type recognized and supported by NBAR.

Note

For a more complete list of the protocol types supported by NBAR, see the "Classifying Network Traffic Using NBAR" module.

How to Configure NBAR Using the MQC

Configuring a Traffic Class

Traffic classes can be used to organize packets into groups based on a user-specified criteria. For example, traffic classes can be configured to match packets on the basis of the protocol type or application recognized by NBAR. In this task, the traffic class is configured to match on the basis of the Citrix protocol type.

Note

The matchprotocolcitrixcommand is shown in Step 4.
Thematchprotocolcitrix command is just an example of one of the matchprotocolcommands that can be used. For a complete list of matchprotocolcommands, see the command documentation for the Cisco IOS release that you are using.

To configure a traffic class, perform the following steps.

Note

Typically, a single traffic class contains one or more match commands that can be used to organize packets into groups on the basis of a protocol type or application. You can create as many traffic classes as needed. However, for Cisco IOS Release 12.2(18)ZY, the following restrictions apply:

A single traffic class can be configured to match a maximum of 8 protocols or applications.

Multiple traffic classes can be configured to match a cumulative maximum of 95 protocols or applications.

>

SUMMARY STEPS

1.enable

2.configureterminal

3.class-map [match-all | match-any] class-map-name

4.matchprotocolcitrix

5.end

DETAILED STEPS

Command or Action

Purpose

Step 1

enable

Example:

Router> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2

configureterminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3

class-map [match-all | match-any] class-map-name

Example:

Router(config)# class-map cmap1

Creates a class map to be used for matching packets to a specified class and enters class-map configuration mode.

Enter the name of the class map.

Step 4

matchprotocolcitrix

Example:

Router(config-cmap)# match protocol citrix

Configures NBAR to match Citrix traffic.

Note

Thematchprotocolcitrix command is just an example of one of the matchprotocolcommands that can be used. For a complete list of matchprotocol commands, see the command documentation for the Cisco IOS release that you are using.

Note

For Cisco IOS Release 12.2(18)ZY, a maximum of 8 matchprotocol commands can be configured in a single traffic class.

Step 5

end

Example:

Router(config-cmap)# end

(Optional) Returns to privileged EXEC mode.

Configuring a Traffic Policy

Traffic that matches a user-specified criterion can be organized into a specific class that can, in turn, receive specific user-defined QoS treatment when that class is included in a policy map.

To configure a traffic policy, perform the following steps.

Note

The bandwidth command is shown in Step 5.
The bandwidth command configures the QoS feature class-based weighted fair queuing (CBWFQ). CBWFQ is just an example of a QoS feature that can be configured. Use the appropriate command for the QoS feature that you want to use.
As of Cisco IOS Release 12.2(18)ZY, CBWFQ is not supported on the Catalyst 6500 series switch that is equipped with a Supervisor 32/programmable intelligent services accelerator (PISA).

Note

For Cisco IOS Release 12.2(18)ZY, an existing traffic policy (policy map) cannot be modified if the traffic policy is already attached to the interface. To remove the policy map from the interface, use the no form of the service-policy command.

(Optional) Specifies or modifies the bandwidth allocated for a class belonging to a policy map.

Enter the amount of bandwidth as a number of kbps, a relative percentage of bandwidth, or an absolute amount of bandwidth.

Note

The bandwidth command configures the QoS feature class-based weighted fair queuing (CBWFQ). CBWFQ is just an example of a QoS feature that can be configured. Use the appropriate command for the QoS feature that you want to use.

Note

As of Cisco IOS Release 12.2(18)ZY, CBWFQ is not supported on the Catalyst 6500 series switch that is equipped with a Supervisor 32/PISA.

Step 6

end

Example:

Router(config-pmap-c)# end

(Optional) Returns to privileged EXEC mode.

Attaching a Traffic Policy to an Interface or Subinterface

After a policy map is created, the next step is to attach the traffic policy (sometimes called a policy map) to an interface or subinterface. Traffic policies can be attached to either the input or output direction of the interface or subinterface.

Note

Depending on the needs of your network, you may need to attach the traffic policy to an ATM PVC, a Frame Relay data-link connection identifier (DLCI), or other type of interface.

To attach a traffic policy (policy map) to an interface, perform the following steps.

SUMMARY STEPS

1.enable

2.configureterminal

3.interfacetypenumber [name-tag]

4.pvc [name] vpi/vci [ilmi| qsaal| smds|l2transport]

5.exit

6.service-policy {input | output}policy-map-name

7.end

DETAILED STEPS

Command or Action

Purpose

Step 1

enable

Example:

Router> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2

configureterminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3

interfacetypenumber [name-tag]

Example:

Router(config)# interface ethernet 2/4

Configures an interface type and enters interface configuration mode.

Enter the interface type and the interface number.

Step 4

pvc [name] vpi/vci [ilmi| qsaal| smds|l2transport]

Example:

Router(config-if)# pvc cisco 0/16

(Optional) Creates or assigns a name to an ATM permanent virtual circuit (PVC), specifies the encapsulation type on an ATM PVC, and enters ATM virtual circuit configuration mode.

This step is required only if you are attaching the policy map to an ATM PVC. If you are not attaching the policy map to an ATM PVC, advance to Step 6
.

Step 5

exit

Example:

Router(config-atm-vc)# exit

(Optional) Returns to interface configuration mode.

Note

This step is required only if you are attaching the policy map to an ATM PVC and you completed Step 4
. If you are not attaching the policy map to an ATM PVC, advance to Step 6
.

Step 6

service-policy {input | output}policy-map-name

Example:

Router(config-if)# service-policy input policy1

Attaches a policy map (traffic policy) to an input or output interface.

Specify either the input or output keyword, and enter the policy map name.

Note

Policy maps can be configured on ingress or egress routers. They can also be attached in the input or output direction of an interface. The direction (input or output) and the router (ingress or egress) to which the policy map should be attached vary according your network configuration. When using the service-policy command to attach the policy map to an interface, be sure to choose the router and the interface direction that are appropriate for your network configuration.

Note

After you use the service-policy command, you may see two messages similar to the following:

While both of these messages appear, NBAR is enabled in the direction specified by the input or output keyword only.

Step 7

end

Example:

Router(config-if)# end

(Optional) Returns to privileged EXEC mode.

Verifying NBAR Using the MCQ

After you create the traffic classes and traffic policies (policy maps), you may want to verify that the end result is the one you intended. That is, you may want to verify whether your traffic is being classified correctly and whether it is receiving the QoS treatment as intended. You may also want to verify that the protocol-to-port mappings are correct.

To verify the NBAR traffic classes, traffic policies, and protocol-to-port mappings, perform the following steps.

SUMMARY STEPS

1.enable

2.showclass-map [class-map-name]

3.showpolicy-map [policy-map]

4.showpolicy-mapinterfacetypenumber

5.showipnbarport-map [protocol-name]

6.exit

DETAILED STEPS

Command or Action

Purpose

Step 1

enable

Example:

Router> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2

showclass-map [class-map-name]

Example:

Router# show class-map

(Optional) Displays all class maps and their matching criteria.

(Optional) Enter the name of a specific class map.

Step 3

showpolicy-map [policy-map]

Example:

Router# show policy-map

Example:

(Optional) Displays the configuration of all classes for a specified service policy map or all classes for all existing policy maps.

(Optional) Enter the name of a specific policy map.

Step 4

showpolicy-mapinterfacetypenumber

Example:

Router# show policy-map interface Fastethernet 6/0

(Optional) Displays the packet and class statistics for all policy maps on the specified interface.

Enter the interface type and the interface number.

Step 5

showipnbarport-map [protocol-name]

Example:

Router# show ip nbar port-map

(Optional) Displays the current protocol-to-port mappings in use by NBAR.

Example Configuring a Traffic Class

In the following example, a class called cmap1 has been configured. All traffic that matches the citrix protocol will be placed in the cmap1 class.

Router> enable

Router# configureterminal

Router(config)# class-mapcmap1

Router(config-cmap)# matchprotocolcitrix

Router(config-cmap)# end

Example Configuring a Traffic Policy

In the following example, a traffic policy (policy map) called policy1 has been configured. Policy1 contains a class called class1, within which CBWFQ has been enabled.

Router> enable

Router# configureterminal

Router(config)# policy-mappolicy1

Router(config-pmap)# classclass1

Router(config-pmap-c)# bandwidthpercent50

Router(config-pmap-c)# end

Note

In the above example, the bandwidth command is used to enable Class-Based Weighted Fair Queuing (CBWFQ). CBWFQ is only an example of one QoS feature that can be applied in a policy map. Use the appropriate command for the QoS feature that you want to use.
As of Cisco IOS Release 12.2(18)ZY, CBWFQ is not supported on the Catalyst 6500 series switch that is equipped with a Supervisor 32/PISA.

Example Attaching a Traffic Policy to an Interface or Subinterface

In the following example, the traffic policy (policy map) called policy1 has been attached to Ethernet interface 2/4 in the input direction of the interface.

Router> enable

Router# configureterminal

Router(config)# interfaceethernet2/4

Router(config-if)# service-policyinputpolicy1

Router(config-if)# end

Example Verifying the NBAR Protocol-to-Port Mappings

The following is sample output of the showipnbarport-map command. This command displays the current protocol-to-port mappings in use by NBAR. Use the display to verify that these mappings are correct.

If the ipnbarport-map command has been used, the showipnbarport-mapcommand displays the ports assigned to the protocol.

If the noipnbarport-mapcommand has been used, the showipnbarport-map command displays the default ports. To limit the display to a specific protocol, use the protocol-name argument of the showipnbarport-map command.

Information about adding application recognition modules (also known as PDLMs)

"Adding Application Recognition Modules" module

Creating a custom protocol

"Creating a Custom Protocol" module

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Feature Information for Configuring NBAR Using the MQC

The following table provides release information about the feature or features described in this module. This table lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.

Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to
www.cisco.com/go/cfn. An account on Cisco.com is not required.

Table 2

Feature Information for Configuring NBAR Using the MQC

Feature Name

Releases

Feature Information

QoS: DirectConnect PDLM

12.4(4)T

Provides support for the DirectConnect protocol and Packet Description Language Module (PDLM). The DirectConnect protocol can now be recognized when using the MQC to classify traffic.

The following sections provide information about the QoS: DirectConnect PDLM feature:

QoS: Skype Classification

12.4(4)T

Provides support for the Skype protocol. The Skype protocol can now be recognized when using the MQC to classify traffic.

Note

Cisco currently supports Skype Version 1 only.

The following sections provide information about the QoS: Skype Classification feature:

NBAR--BitTorrent PDLM

12.4(2)T

Provides support for the BitTorrent PDLM and protocol. The BitTorrent protocol can now be recognized when using the MQC to classify traffic.

The following sections provide information about the NBAR-BitTorrent PDLM feature:

NBAR--Citrix ICA Published Applications

12.4(2)T

Enables NBAR to classify traffic on the basis of the Citrix Independent Computing Architecture (ICA) published application name and tag number.

The following sections provide information about the NBAR-Citrix ICA Published Applications feature:

NBAR--Multiple Matches Per Port

12.4(2)T

Provides the ability for NBAR to distinguish between values of an attribute within the traffic stream of a particular application on a TCP or UDP port.

The following sections provide information about the NBAR-Multiple Matches Per Port feature:

NBAR Extended Inspection for HTTP Traffic

12.3(4)T

Allows NBAR to scan TCP ports that are not well known and identify HTTP traffic that traverses these ports.

The following sections provide information about the NBAR Extended Inspection for HTTP Traffic feature:

Integrates NBAR and Firewall Service Module (FWSM) functionality on the Catalyst 6500 series switch that is equipped with a Supervisor 32/programmable intelligent services accelerator (PISA). Additional protocols are now recognized by NBAR.

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www.cisco.com/go/trademarks. Third-party trademarks mentioned are the property of their respective owners. The use of the word partner does not imply a partnership relationship between Cisco and any other company. (1110R)

Any Internet Protocol (IP) addresses and phone numbers used in this document are not intended to be actual addresses and phone numbers. Any examples, command display output, network topology diagrams, and other figures included in the document are shown for illustrative purposes only. Any use of actual IP addresses or phone numbers in illustrative content is unintentional and coincidental.

1 Cisco IOS match protocol commands can vary by release. For more information, see the command documentation for the Cisco IOS release that you are using.